The NonExclusiveDeviationAlarmType is a special level Alarm utilized with one or more non-exclusive states. If for example both the High and HighHigh states need to be maintained as active at the same time then an instance of NonExclusiveDeviationAlarmType should be used.

The NonExclusiveDeviationAlarmType is based on the NonExclusiveLimitAlarmType. It is formally defined in Table 101.

Table 101 – NonExclusiveDeviationAlarmType definition

Attribute

Value

BrowseName

NonExclusiveDeviationAlarmType

IsAbstract

False

References

NodeClass

BrowseName

DataType

TypeDefinition

ModellingRule

Subtype of the NonExclusiveLimitAlarmType defined in clause 5.8.20.

HasProperty

Variable

SetpointNode

NodeId

PropertyType

Mandatory

HasProperty

Variable

BaseSetpointNode

NodeId

PropertyType

Optional

ConformanceUnits

A & C Non-Exclusive Deviation

The SetpointNode Property provides the NodeId of the set point used in the deviation calculation. In cases where the Alarm is generated by an underlying system and if the Variable is not in the AddressSpace, a NULL NodeId shall be provided.

The BaseSetpointNode Property provides the NodeId of the original or base setpoint. The value of this node is the value of the setpoint to which an AdaptiveAlarm can be reset if any algorithmic changes need to be discarded. The value of this node usually contains the originally configured set point.